1. Field of the Invention
The present invention is directed to a tankless water heater assembly which is specifically adapted to heat water on a continuous basis as it passes from a conventional water source along a path of water flow through the system and into heat transferring relation to spaced apart, substantially segregated heating elements interconnected by more than one water directing connecting ports.
2. Description of the Prior Art
The most commonly used water heater assemblies for both domestic and commercial use involves the utilization of a rather large storage tank for water. Inefficiency is prevalent in these types of water heater assemblies due to the fact that the water maintained within such storage tanks is effectively reheated even when the water is not being utilized on a regular basis. To the contrary, an existing alternative to such storage tank water heater is the continuous flow or "tankless" water heaters wherein the water is almost instantaneously heated as it passes through the continuous flow system. It is recognized in the prior art that the tankless water heater assemblies are far more efficient from the standpoint of expending energy for the purpose of only heating water which is currently being used. However, such prior art continuous flow water heaters are also recognized as being significantly limited in flow delivery capacity by the heat input available. Such normal or existing factors in the continuous flow water heaters restrict the available hot water temperatures to less than satisfactory levels for a continuous flow requirements needed by most domestic and certainly by almost all commercial users.
An additional disadvantage associated with continues flow or "tankless" water heaters known in the prior art is their inability to actively regulate the output temperature as flow rates fluctuate without the use of expensive and complex controls. Another existing and well recognized problem associated with such type of instantaneous water heaters is their lack of reliability and their frequent break down or need for maintenance and repair. To a large extent this is caused by the inability to distribute equally and/or proportionately water between each of a plurality of individual heating units as water passes continuously through the heating system. Also the ability to remove, replace and/or repair the heating elements if a breakdown occurs would be of considerable advantage from a maintenance standpoint although such features are not well recognized in prior art and/or known in continuous flow water heaters of the type referred to herein.
The following patents are generally representative of continuous flow water heaters of the type referred to herein. The patent to Insley, U.S. Pat. No. 4,762,980 discloses an apparatus for electrically heating water utilizing at least two electrically powered heating resistance elements disposed sequentially along a path of flow but wherein separate chambers in which the separate heating elements are arranged are connected by a single common port or opening located at a common end of both the chambers and heating elements. Insley discloses his heating elements as a continuous electric resistance heating coil extending successfully through separate interior channels rather than two totally segregated elements. The heating coils controlled by temperature controller means having a temperature sensor to reduce or eliminate the effects of radiant energy generated by the heating coil on the temperature sensor. Insley also suggests the use of a TRIAC to regulate current flow to the continuous electric resistance heating coil. Insley does not show two spaced apart and effectively segregated heating coils each having electrical current being directed thereto under regulation by separate TRIACS such that proportional current flow may be directed when separately or concurrently activating the heating elements.
Eddas discloses an instantaneous fluid heater having a plurality of electrical heating elements wherein current is directed to the heating elements through control by means of a solid state switch and the use of a TRIAC type switch. Eddas therefore attempts to provide an instantaneous type water heater having temperature regulation to permit stored water to be maintained at a constant temperature while utilizing a plurality of heating elements as well as structure which is adapted to interrupt the flow of power through the heating elements when the fluid temperature exceeds an established pre-determined temperature. Eddas does not show the utilization of a flow control switch for purposes of initial activation nor does he completely describe the use of spaced apart segregated heating elements wherein water passes between the respective heating elements by a plurality of ports or channels which are proportionally dimensioned so that water flow may be exposed to the heating elements at different points along their length and in different amounts at such point.
Hurko, U.S. Pat. No. 4,808,793 discloses a tankless electric water heater having an instantaneous hot water output which includes an open ended folded tubular conduit having a separate metal sheath emerging heating element inserted into each end of the conduit. This patent also discloses the use of self regulating (PTC) heating cable either disposed in or wrapped around the tubular conduits which is continuously energized independently of the metal sheathed heating elements so as to maintain the water in the tubular conduits at a constant pre-determined temperature.
Davidson, U.S. Pat. No. 4,604,515 discloses a plurality of separate, serially connected heating chambers defining a water flow path from a cold water inlet port to a heated water outlet port wherein each chamber is provided with a separate heating element and a separate temperature sensor for producing a signal indicative of the water temperature within that chamber. Each of the heating elements are independently controlled by a control assembly responsive to signals from the temperature sensors in the respective heating chambers. By virtue of this assembly, each of the heating elements in a given chamber is energized only if the sensed water temperature in that chamber is too low.
Todd, U.S. Pat. No. 4,567,350 discloses an instantaneous electric water heater for both household and commercial use including a plurality of sequentially arranged individual heating chambers connected in series flow relationship between a cold water inlet and a hot water outlet wherein heating elements are energized by a flow switch at the time the hot water is demanded and are controlled by an adjustable thermostat which sets the outlet hot water temperature. An adjustable regulator is provided to assure that the water flow rate will not exceed the capacity of the heater to heat the water to a minimal acceptable level. It is important to note that there is no teaching in this patent of a plurality of proportionately dimensioned interconnecting ports so as to transfer or allow water flow between the chambers and into heat transferring engagement with the heating elements therein at various points along the length or dimension of the heating chamber so as to eliminate any exposure of the heating element to air when activated and thereby eliminate or seriously reduce the possibility of burnout.
Other U.S. patents relating to the subject of continuous flow water heaters include Maus, U.S. Pat. Nos. 4,900,896; Swindle, 4,467,178; Loeffalr, 4,823,770; Lutz et al, 4,970,373.
Based on the above there is still a need for an efficient high capacity continuous flow water heater which of course eliminates the problems and inefficiencies associated with storage tank water heaters and also which is capable of delivering an ample supply of hot water on a continuous basis and within acceptable temperature ranges. Such a preferred continuous flow water heater assembly should eliminate the problems of maintenance by significantly reducing the likelihood or possibility of burn outs of the one or more heating elements associated therewith.